Charging device for combustion machines



F. PORSCHE CHARGING DEVICE FOR COMBUSTION MACHINES Filed Jan! 14. 1925 PL W Patented Aug. 23, 1927..

UETED STATS PATENT ()FFIQEZ.

FERDINAND PORSCHE, OF STUTTGART-UNTERTURKHEIM, GERMANY, ASSIGNOR, BY MESIN'E ASSIGNMENTS, 'I'O DAIMLER-BENZ AKTIENGESELLSCHAFT, 0F BERLIN,

GERMANY.

CHARGING DEVICE FOR COMBUSTION MACHINES.

Application filed January 14, 1925,'Seria1 No. 2,458, andin Germany April 30, 1923.

The present invention relates to combustion engines with which the fuel tank is situated lower than the carburettor. In such case it is necessary, in order to cause the fuel to flow from the tank to the carburettor, either to produce an over-pressure in the fuel tank (which must suitably be constructed for this purpose) and fitted with an air pump, or to arrange a suction apparatus between the tank and the carburettor.

If the said combustion engines, the fuel tanks of which are situated below the carburettor, are fitted out with a blower for the purpose of delivering air under overpressure to the motor, for the purpose of supercharging same for a short time, it is obvious that during this period of supercharging, the motor and carburettor are being put under over-pressure. Consequently the normal delivery of fuel from the low tank to the carburettor is in such case no longer possible.

For the purpose of over-pressure fuel conduction from main tank to carburettor, constructions have been provided, by which a continuous fuel supply to the carburettor during the overload period was secured. Over-pressure fuel conduction, however, has the drawback that the main fuel tank must be constructed according to the over-pres sure therein and this leads to a main tank of considerable weight,

Up to now no construction has been suggested by which a continuous fuel supply to the carburettor, whilst overloading, was secured in connection with a machine the main fuel tank with which is situated lower than the carburettor and whereby the fuel transport from main tank to carburettor is operated by a suction apparatus.

The object of the present invention is to secure a continuous fuel supply to the motor, during the period of supercharging, in connection with a combustion engine, the main fuel tank of which is situated lower than the carburettor and whereby the transport of the fuel from the main tank to the carburettor is operated by a suction apparatus.

Another object of the present invention is that the arrangement which is provided for securing a continuous fuel delivery during the supercharging period, is put in action automatically, as soon as the overloading compressor delivers air under overpressure; and further that whilst supercharging, no fuel is taken from the main tank.

An example of carrying this invention into effect is represented in the accompanying drawing, of which Fig. 1 shows in a section a vehicle frame together with the motor and the conveyor or suction device according to this invention, Fig. 2 is a plan view of the same and Fig. 3 shows in an enlarged scale the suction device for the fuel.

According to the present invention an auxiliary fuel container 8 has been provided for, in the fuel conduit Z, between main tank e and carburettor d This auxiliary fuel container 8 is situated above the level of the carburettor (Z. lV hen supercharging the auxiliary fuel container 8 is put under the same over-pressure as the carburettor (Z and according to the high position of the former, the fuel contained therein flows to the carburettor d by reason of its own weight.

It will be understood that the length of the supercharging period depends on the capacity of the auxiliary fuel container 8, that is to say of the quantity of fuel this tank can contain.

According to the object of the present invention this auxiliary fuel container 8 is automatically put under atmospheric pressure as soon as the overload period is at an end, that is to say when the overloading compressor 1) no longer delivers air under over-pressure into the admission chamber 2' of the motor a.

In order to put. the auxiliary container 8 under over-pressure,whilst overloading, and to put it under atmospheric pressure whilst running under normal conditions, the following means are provided. A three way connection is made between the top of the auxiliary container 8, the carburettor d' of the motor a and the atmosphere.

In the'three way connection a valve y is provided which under conditions of normal load puts the auxiliary container 8 in con nection with the atmosphere and shuts it off from the carburettor d of the motor a. Incidentally when during the period of supercharging the compressor .7) puts the ill) IOU

admission chamber 2' and the carburettor (Z of the motor under over-pressure, this valve y links the container 8 to the carburettor (Z, thus putting the former under the pressure of thelaiter and shutting it off from the osphere.

the suction apparatus consists of a suc tic-n chamber which communicates with the main tank 6 by an open fuel transmission pipe, Z, and by means of a suction pipe 7b and valve w with the admission chamber 2' of the motor a.

The suction chamber is which is situated above the auxiliary container 8 communicates with the latt by a fuel admission pipe provided with a check valve 7.

Under conditions of normal load, the fuel, which operated by the suction appara tus f, has been transmitted from the main fuel tank 6 to the suction chamber 7;, drops from the suction chamber through the fuel pipe and check valve 7* into the auxiliary container 8 and by reason of its proper weight, flows from the auxiliary container to the carburettor d.

It, when running under normal load, incidentally the auxiliary container .9 and the suction chamber is becomes filled with fuel, a flout m shuts the suction valve w in the suction pipe /L oi the suction chamber A: and at the same time opens a valve 2, which admits atmospheric pressure into the suction chamber 0, thus cutting off the operation of the suction apparatus It is obvious that to prevent loss of fuel, the connection of the auxiliary container 8 with the atmosphere must be situated above the :tuel level tolerated by the float m in the suction chamber is.

When supercharging, the auxiliary container s is put under the over-pressure of the carburettor (Z of the motor, in the manner as described above. Due to the overpressure .in the container 8, the check valve r in the connection pipe of suction chamber is and container 3 is closed and thus the we tainer s is shut oil from the suction chamber 7c. By reason of its proper weight the fuel stored in the auxiliary container 8 continues to flow to the carburettor (Z, which with the container 8 by means 01" the blower b is put under the same over-pressure as the admission chamber Simultaneously herewith the suction pipe 7b of the suction chamber Z5 and which pipe ii. is correspond ng with the adn'rission chamber 2' of the motor a, is put under overpressure, causing tne valve w arranges in the suction pipe ii to close and thus to cut off the operation of the suction apparatus 7. During the super-charging period no fuel is transmitted from the maintanlr c to the suction chamber Zn.

it is a characteristic feature of the present invention: 7

1. That during the period oi superchargng, the auz; iary container 3 is put under re over-pi ire of the admission chamber shutting thereby of said auxiliary con- 'ai ;er

s from the suction chamber 76; ihat the fuel supply to the carburettor (Z is continued "from the container 8 and;

3, That at the same time the operation of the suction apparatus 7" is cut oii i .l claim A fuel feeding system for that type of auto vehicle construction in which the main fuel reservior is lower than the carburettorof the engine and in which the normal vacuum in the intake manifold is intermittently changed to over-pi ssure by the use ot a supercharger, comprising, a vacuum tanl; comn'iunicating with a main fuel reservoir, an aux liary tank communicating with the carburettor oi the engine, said auxi iary tanl: being in one-way communication with said vacuum tank to receive-fuel from the latter, a c nduit connecting vacuum S'zliu tank with region of the engine in which the normal vacuum alternates with overpressure from the supercharger when the latter is operated, a conduit connecting said auxiliary tank with a rcs ion of the engine subject to over-pressure or the supercharger, and a check valve in sait i duit o ierative upon the simtltaneous application of over-pressure to both said conduits, to close said first narned conduit against communication with the main t'uel reservoir. In testimony whereof I anii: my signature.

FERDINAND FQRSCI first I named COD? 

